diff --git a/includes/common.inc b/includes/common.inc
index 40a7919..e42062a 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -1074,6 +1074,14 @@ function drupal_http_request($url, array $options = array()) {
       }
       elseif ($options['max_redirects']) {
         // Redirect to the new location.
+
+        // If the location is a relative path, we need to add it to the existing
+        // scheme and host.
+        $location_uri = @parse_url($location);
+        if ($location_uri !== FALSE && empty($location_uri['scheme'])) {
+          $location = $uri['scheme'] . '://' .  $uri['host'] . $location;
+        }
+
         $options['max_redirects']--;
         $result = drupal_http_request($location, $options);
         $result->redirect_code = $code;
diff --git a/modules/simpletest/tests/common.test b/modules/simpletest/tests/common.test
index 44eecdc..e2a5a7a 100644
--- a/modules/simpletest/tests/common.test
+++ b/modules/simpletest/tests/common.test
@@ -1033,9 +1033,8 @@ class DrupalHTTPRequestTestCase extends DrupalWebTestCase {
     $redirect_301 = drupal_http_request(url('system-test/redirect/301', array('absolute' => TRUE)), array('max_redirects' => 0));
     $this->assertFalse(isset($redirect_301->redirect_code), 'drupal_http_request does not follow 301 redirect if max_redirects = 0.');
 
-    $redirect_invalid = drupal_http_request(url('system-test/redirect-noscheme', array('absolute' => TRUE)), array('max_redirects' => 1));
-    $this->assertEqual($redirect_invalid->code, -1002, format_string('301 redirect to invalid URL returned with error code !error.', array('!error' => $redirect_invalid->error)));
-    $this->assertEqual($redirect_invalid->error, 'missing schema', format_string('301 redirect to invalid URL returned with error message "!error".', array('!error' => $redirect_invalid->error)));
+    $redirect_301 = drupal_http_request(url('system-test/redirect-noscheme', array('absolute' => TRUE)), array('max_redirects' => 1));
+    $this->assertEqual($redirect_301->redirect_code, 301, 'drupal_http_request follows the 301 redirect for a relative location.');
 
     $redirect_invalid = drupal_http_request(url('system-test/redirect-noparse', array('absolute' => TRUE)), array('max_redirects' => 1));
     $this->assertEqual($redirect_invalid->code, -1001, format_string('301 redirect to invalid URL returned with error message code "!error".', array('!error' => $redirect_invalid->error)));